For now, at least, the “ground zero mosque” in New York and threats to burn copies of the Quran are no longer front-page news. But Americans remain wary of Islam as the FBI and other law enforcement agencies investigate a growing list of attacks on mosques and threats to Muslims.

The picture on public attitudes is mixed, according to a recent report by the Pew Forum on Religion and Public Life, which finds that opinions about Islam are less favorable now than they were five years ago.

For example, a plurality of those surveyed (42 percent) say Islam does not encourage violence more than other religions. Still, a substantial minority – 35 percent – believe Islam to be more violent than other faiths.

While the reasons for this have not been pinned down, two factors likely are involved: Recent terrorist threats and attempted attacks in the United States (the Fort Hood shootings, the Christmas Day and Times Square bomb attempts, the fatal shooting at a US Army recruiting office), plus controversies around the country involving new mosques.

Most recent available figures show a 57 percent increase in the number of mosques in the United States over the past ten years – from 1,209 to 1,897. While opposition often is tied to local zoning and traffic issues, the Justice Department's Civil Rights Division said this past week that it is monitoring 11 cases of potential land-use discrimination against Muslims – eight of those cases opened since May.